(a) Technical Field
The present invention relates to an image display device, and more particularly, to a three dimensional image display device and a driving method thereof.
(b) Discussion of the Related Art
Generally, a three-dimensional (3D) image display device displays three dimensional perception of objects by using binocular parallax, which is the primary factor in recognizing a 3D feeling at a short distance. In binocular parallax, different two-dimensional (2D) images are projected onto a left eye and a right eye. When the images projected onto a left eye (hereinafter, “left eye image”) and the images projected onto a right eye (hereinafter, “right eye image”) are transferred to a brain of a viewer, the left eye image and the right eye image are mixed in the brain and thus are perceived as a 3D image having depth.
Some 3D image display devices relying upon binocular parallax may use a stereoscopic method in which glasses such as shutter glasses, polarized glasses, etc., are used. Other 3D display devices relying upon binocular parallax may use an autostereoscopic method without glasses where a lenticular lens, a parallax barrier, etc., are disposed on a display device.
When shutter glasses are used, the left eye image frames and the right eye image frames are alternately displayed in the 3D image display device using a technique known as alternate-frame sequencing. The 3D images are then perceived by the viewer by selectively opening and closing a left eye shutter and a right eye shutter of the shutter glasses so that image frames including the left eye image are only seen by the left eye while image frames including the right eye image are only seen by the right eye.
Display devices employing the shutter glasses method may thereby be capable of displaying 2D images in a 2D mode where every frame is intended for both left and right eyes and then may be switched to a 3D mode that is capable of displaying 3D images where alternating left eye and right eye image frames are displayed. In such a display, there may be no data loss in either mode. However, as the shutter glasses worn in the 3D mode rely on the closing of shutters for every other image frame, the luminance of the three dimensional image display device may be reduced as half of the image frames to not reach the eyes of the viewer. Moreover, as many shutter glasses utilize polarized lenses, additional luminance may be lost.